What is frontend-testing?

A set of instructions for testing web interfaces, application programming interfaces (APIs), and browser workflows. It covers unit tests, component tests, Storybook checks, coverage, and Playwright end-to-end tests.

Use it when changing Vitest or Testing Library tests, API-domain tests, Storybook stories, coverage settings, or Playwright browser tests.

It helps keep tests focused on user-visible behavior and reminds you to check failures, cancellation, accessibility, and coverage consistently.

frontend-testing — Cursor rule by williamisnotdefined

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods

npx agentmods add rules/williamisnotdefined/rubiks-cube-solver/frontend-testing

Clone the repo

git clone --depth 1 https://github.com/williamisnotdefined/rubiks-cube-solver

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.

When invoked 3,465 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5	$0.00000	$0.03465
Opus 5	$0.00000	$0.01733
Sonnet 5	$0.00000	$0.00693
Haiku 4.5	$0.00000	$0.00347

Measured 2d ago against content hash 73119bc3038e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

frontend-testing scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/frontend-testing.mdc · 222 lines

How it starts

The opening of the file, as written. The whole thing — 222 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Generated from ai/registry.json. Do not edit manually.

Canonical skill: ../../ai/skills/frontend-testing.md.

Referenced context:

../../ai/rules/frontend-rules.md
../../ai/rules/testing-rules.md
../../ai/rules/frontend-quality-rules.md
../../ai/architecture/web-architecture.md

This file is compiled from canonical AI knowledge files. Edit canonical files under ai, then run npm run ai:sync.

Compiled AI Skill: frontend-testing

Canonical Skill: `ai/skills/frontend-testing.md`